Azo dye.



UNITED STATES PATENT OFFICE.

MYRTIL KAI-IN AND ANTON OSSENTBECK. 0F ELBERFELD, GERMANY, ASSIGNORS TO FARBENFABRIKEN VORM. FRIEDR. BAYER & GO.. OE ELBERFELD, GERMANY. A

CORPORATION OF GERMANY.

AZO DYE.

No Drawing Patented May 14, 1912.

Serial No. 658,151.

To all whom, it may concern Be it known that we, MYRTIL KAHN and ANToN OssENBEeK, doctors of philosophy, chemists, citizens of the German Empire, residing at Elberfeld. Germany, have invented new and useful Improvements in' New Azo Dyes, of which the following is a specification.

Our invention relates to the manufacture and production of new tetrakisazo dyestuffs. The process for their production consists in combining with one molecule of a metadiaminodiphenylurea compound such as meta-diaminodiphenylurea or ditolylurea two molecules of an intermediate compound obtained from one molecule of a tetrazo compound of a diamin, such as benzidin, tolidin, para-phenylenediamin and one molecule of a meta aminophen ol sulfonic acid. The new dyes are after being dried and pulverized dark powders yielding upon reduction with stannous chlorid, and hydr0- ehloric acid a d amin, triaminobenzene compounds. diaminophenol sulfonic acid and carbonic acid, dyeing cotton generally orange shades which on being diazotized and combined with meta-phenylenediamin turn into fast shades.

In order to illustrate the new process more fully the following example is given, the parts being by weight: 18.4 parts of benzi'din are tetrazotized in the known manner with 14 parts of nitrite and the tetrazo compound is combined with a solution of 19 parts of meta-aminophenol sulfonic acid. To complete the formation of the intermediate product soda is slowly added to the mixture while it is being well stirred. The excess of soda is then neutralizedand a solution of 17.5 parts of the hydrochlorid of meta-diaminodiphenylurea is added and sodium acetate until the mixture reacts neutral to Congo-paper. It is stirred for several hours at ordinary temperature and afterward for the same time at 50 C. care being taken to neutralize the acid which is liberated. The combination is complete after the mixture has been stirred for about one day. The solution is then rendered alkaline and the dyestuft is salted out. filtered off and dried. The dyestutf thus obtained having probably the following formula:

is after being dried and pulverized a dark brown powder which is soluble in water with a brown coloration and iircoiicenti'ated sulfuric acid with a violet coloration; yielding upon reduction with stannous chlorid and hydrochloric acid benzidin. diaminophenol sulfonic acid, 1.QAl-triaminobenzene and carbonic acid. It dyes umnordanted cotton in orange shades which on being diazotized and combined with meta-phenylene diamin turn into a yellowish-brown of good fastness.

Instead of benzidin other para-diamins. instead of the meta-aminophenol sulfonio acid the meta-aminocresol sulfonic. acid and instead of mcta-diaminodiphenylurea meta diaminoditolylurea can be used.

e claim:

1. The herein described new tetrakisazo dyestuffs, which are after being dried and pulverized dark powders yielding upon reduction with stannous chlorid and hydrochloric acid a diamin, triaminobenzene compminds. a diaminophenol sulfonic acid and carbonic acid: dyeing cotton. generaltv orange shades which on being diazotizcd and combined with lneta-phenylenediamin turn into yellowish-brown shades of good fastness, substantially as described.

2. The herein described new tetrakisazo dyestufi's, which is after being dried and pulverized a dark brown powder which is soluble in Water with a brown coloration and in concentrated sulfuric acid with a violet coloration; yielding upon reduction nylenediamin turn into a yellowish-brown of good fastness, substantially as described. In testimony whereof we have hereunto scribing witnesses.

MYRTIL KAHN. [L. s.] W1th stannous chlorld and hydrochlorlc acld benzidin, diaminophenol sulfonic acid, ANTON OSSENBELK 1.2.4-triaminobenzene and carbonic acid; VVit-nesses:

dyeing cotton orange shades which on being ALBERT Nurnn, diazotized and combined with meta-phe- HELEN NUFER.

Joples of this patent may be obtained for five cents each, by addressing the Commissioner of Yatents, Washington, 1). 0."

set our hands in the presence of two sub- 15 

